Our sequence of
operations on the first night of the Luftwaffe's blitz on
London was as follows. First we would check on our receiver
at Alexandra Palace the carrier frequency being used by the
enemy in Normandy on their latest Y-Gert radar system. This
we did during the Luftwaffe's warm-up testing period prior
to their take-off to bomb London and/or the Home Counties.
Little was ever known about precise intentions, but at least
we made doubly sure that our transmitter would be tuned to
precisely the correct frequency, to ensure that our radar
countermeasures were totally effective.

Later on, of course, they
tried changing their radar frequencies (wavelengths) to
catch us out, but we were ready for all their tricks. It
took us nearly ten minutes to retune all our stages of RF
circuits in the transmitter, which was not easy to do under
pressure of impending attack. The Luftwaffe only needed
thirty minutes from take-off before bombing over
London.

Our other safeguard was
provided by our operators as Swains Lane receiver station at
Highgate, a few miles away but connected by Post Office
land-line to AP transmitter. By using a low-voltage motor,
this line controlled any drifting in our lock-on carrier
beam, thus eliminating any give-away heterodyning
beat-notes. On red alert, full power was applied at the
Transmitter HT Control Desk, where I had every facility for
meter-checking and listening on headphones to the young
Luftwaffe pilots trying unsuccessfully to contact their HQ
in northern France amidst confused instructions.

On the first night, our
full-power intervention from the AP transmitter to the
pilot's receiver caused enemy radio communication to get out
of hand, leading to panic calls first blaming their own
Y-Gert for failure, then HQ for false readings and finally
each other for meter errors by which time our own AA firing
power was at maximum. Even AP's own glass roof joined in the
crashing chaos going on above. But the bombs we were
expecting never arrived.

There were three of us on
duty in the Transmitter Control Room at AP with others on
standby, but we were all exhausted with nervous tension. We
were never sure what was coming next. It was a night of
dramatic failure for Y-Gert and those highly trained young
pilots too scared to take bombing initiative or get shot on
returning to base.

Chaos ruled supreme, and
the following night I again decided to go for full-power,
(despite restraining advice which came too late), as there
was no time for 'phoning or indecision. And again the
results were successful. Rightly or wrongly, it worked,
which was all that mattered.

By chance we were right.
It was full power that blasted the enemy Y-Gert system to
'kingdom come', which shattered German pilot confidence for
good. The next night I reduced power slightly until our
meters were stable and happy, whilst our headphones still
registered complete chaos overhead. After the 'All Clear'
went, that was the first night we slept well.

I had always been scared
of seeing another Coventry disaster over London caused by
mistakes in checking enemy radar frequencies, which rendered
our own countermeasures useless, leaving the Luftwaffe in
full control of radio communication for bombing selected
targets. We were fortunate at AP, where we used double
checking on all enemy frequencies.

I would now like to try
to conjure up the state of the art, including the
psychological state of my mind when I was sent back from
Dorset to Alexandra Palace following the dreadful cock-up at
Coventry. "This must never happen again", was the message
that kept going round in my mind, knowing full well from our
local knowledge when the Heinkel came down on the beach at
Bridport, that the next nightly blitz by the Luftwaffe was
to be London.

Naturally, imagined that
I had been selected as a junior technician to join the team
of experts who had already started modifying the television
transmitters to destroy the latest enemy radar system,
Y-Gert, which had not yet been used. To my horror, when I
arrived back at Ally Pally and rang the front door bell, I
was greeted by the caretaker, who informed me that all the
senior television expert engineers had finished the
modifications and had left London. I then met our cleaner,
named Myers, who always used to make our tea on night shift,
and he told me that Mr T H (Tony) Bridgewater was still
there. Naturally I was delighted and after receiving a full
report on the present situation, I learned that he was
leaving the BBC to join the RAF at Radlett.

When I recovered, I
decided to go straight to Broadcasting House to see Mr
Hotine, Superintendent Engineer Transmitters (S.E.T.). When
I told him there were no operational engineers left at AP,
he immediately 'phoned Daventry for volunteers. But there
were none and I could hardly blame them as Ally Pally was on
Haw-Haw's list and Ministry of Defence were sending RAF
operational staff anyway.

I had been warned about
'phoning regarding operations, due to [the risk of] tapping,
and there is no doubt that Haw-Haw, who knew Ally Pally
backwards, had got wind of this administration cock-up.
Because shortly afterwards, when I returned to Ally Pally, I
discovered that Bill Jackson, my pre-war assistant, was
still living at AP, awaiting a transfer to another job.
Fortunately he had been trained on 'frequency changes' on
our transmitters, so I was able to pick up all the necessary
information. However, I did query with him why TRE had been
appointed by the Ministry of Defence to use our obsolete
receiving station at Highgate as a control centre using a
Post Office land-line; that was in itself a risky operation.
Jacko (as I always called him), seemed a bit embarrassed but
also seemed to be agreeing with my queries, when suddenly
there was a hell of a whistle and a terrific explosion
outside, rattling the glass roof and windows. We both ran
like hell for the front door and flew into the one and only
steel bell shelter. We were both white and
shaken.

Later we discovered that
there had been a stick of six high-explosive bombs aimed
parallel to the front facade in line with both our sound and
vision transmitters, about 100 yards short to the south.
After leaving, Jacko sent me his report, with which I fully
agreed.

So my querying the
Ministry of Defence's decision to do radio monitoring of
enemy radar frequency-checking from our decrepit receiving
station at Swains Lane, Highgate, proved to be valid. In
fact an investigation proved that the frequency calibration
of the pre-war receiver in use was not up to standards
required for checking enemy radar systems. Owing to the
complicated line of command between TRE, the RAF 80 Wing
Radlett and the BBC, this near catastrophe has remained
under the carpet with other. One good thing came out. Six
RAF technicians and a few BBC engineers arrived post-haste
to man 'Domino' at Ally Pally.

The obvious conclusions
from this experience is that TRE's failure to check enemy
radar frequencies accurately at Coventry, was repeated at
Swains Lane, Highgate, where TRE chose to carry out their
monitoring of enemy radar frequency-checking. Unlike
Coventry, by sheer luck Alexandra Palace was not flattened
out of existence. The final conclusion is that TRE personnel
should not have taken on operations duties but should have
left these to professional engineers trained in that work.
And eventually that was what happened at Alexandra Palace,
where we doubled-checked each and every vital operation
which finally obliterate the enemy Y-Gert radar
system.